19.2 problem section 9.3, problem 2

Internal problem ID [1499]

Book: Elementary differential equations with boundary value problems. William F. Trench. Brooks/Cole 2001
Section: Chapter 9 Introduction to Linear Higher Order Equations. Section 9.3. Undetermined Coefficients for Higher Order Equations. Page 495
Problem number: section 9.3, problem 2.
ODE order: 3.
ODE degree: 1.

CAS Maple gives this as type [[_3rd_order, _linear, _nonhomogeneous]]

\[ \boxed {y^{\prime \prime \prime }-2 y^{\prime \prime }-5 y^{\prime }+6 y={\mathrm e}^{-3 x} \left (6 x^{2}-23 x +32\right )} \]

Solution by Maple

Time used: 0.016 (sec). Leaf size: 37

dsolve(diff(y(x),x$3)-2*diff(y(x),x$2)-5*diff(y(x),x)+6*y(x)=exp(-3*x)*(32-23*x+6*x^2),y(x), singsol=all)
 

\[ y \left (x \right ) = \frac {\left (4 c_{3} {\mathrm e}^{6 x}+4 \,{\mathrm e}^{4 x} c_{1} +4 c_{2} {\mathrm e}^{x}-x^{2}+x -3\right ) {\mathrm e}^{-3 x}}{4} \]

Solution by Mathematica

Time used: 0.01 (sec). Leaf size: 45

DSolve[y'''[x]-2*y''[x]-5*y'[x]+6*y[x]==Exp[-3*x]*(32-23*x+6*x^2),y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to -\frac {1}{4} e^{-3 x} \left (x^2-x+3\right )+c_1 e^{-2 x}+c_2 e^x+c_3 e^{3 x} \]